function Bomb(){
    this.start = function (){
        setTimeout(function(){
        console.log("炸弹爆炸BOMO BOMB BOMB");
    },3000);}

    this.clear = function(){
        clearTimeout(this.start);
    }

}

var b1 = new Bomb();
b1.start();
var b2 = new Bomb();
b2.start();
setTimeout(b2.clear,1000);